The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds. XI. Lupus Observed With IRAC and MIPS

Abstract

We present c2d Spitzer/IRAC observations of the Lupus I, III and IV dark clouds and discuss them in combination with optical and near-infrared and c2d MIPS data. With the Spitzer data, the new sample contains 159 stars, 4 times larger than the previous one. It is dominated by low- and very-low mass stars and it is complete down to M $\approx$ 0.1M${}_{\odot }$. We find 30-40 % binaries with separations between 100 to 2000 AU with no apparent effect in the disk properties of the members. A large majority of the objects are Class II or Class III objects, with only 20 (12%) of Class I or Flat spectrum sources. The disk sample is complete down to ``debris''-like systems in stars as small as M $\approx$ 0.2 M${}_{\odot }$ and includes sub-stellar objects with larger IR excesses. The disk fraction in Lupus is 70 -- 80%, consistent with an age of 1 -- 2 Myr. However, the young population contains 20% optically thick accretion disks and 40% relatively less flared disks. A growing variety of inner disk structures is found for larger inner disk clearings for equal disk masses. Lupus III is the most centrally populated and rich, followed by Lupus I with a filamentary structure and by Lupus IV, where a very high density core with little star-formation activity has been found. We estimate star formation rates in Lupus of 2 -- 10 M${}_{\odot }$ Myr${}^{-1}$ and star formation efficiencies of a few percent, apparently correlated with the associated cloud masses.

Accepted for publication in the ApJS. Contains 101 pages, 23 figures, and 13 tables. A version with full resolution figures can be found at http://peggysue.as.utexas.edu/SIRTF/PAPERS/pap102.pub.pdf

References in corpus (11)

• Dust dynamics during protoplanetary disc clearing
• Binarity as a key factor in protoplanetary disk evolution: Spitzer disk census of the eta Chamaeleontis cluster
• Young, Low-Mass Brown Dwarfs with Mid-Infrared Excesses
• The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds.X. The Chamaeleon II Pre-Main Sequence Population as Observed With IRAC and MIPS
• Empirical isochrones and relative ages for young stars, and the radiative-convective gap
• Medium-separation binaries do not affect the first steps of planet formation
• SPITZER: Accretion in Low Mass Stars and Brown Dwarfs in the Lambda Orionis Cluster
• New Low-Mass Stars and Brown Dwarfs with Disks in Lupus
• Giant Planet Migration in Viscous Power-Law Discs
• The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds. IV. Lupus Observed with MIPS
• WWW Database of Models of Accretion Disks Irradiated by The Central Star

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